Heater arrangement for hvac system

ABSTRACT

A heating, ventilation, and air conditioning (HVAC) system comprises a housing defining a chamber configured to receive a first air flow and a second air flow. The chamber comprises a vacant section and a heating section, and the heating section comprises a heating coil. A first blower is configured to direct the first air flow into the vacant section of the chamber and a second blower is configured to direct the second air flow into the heating section of the chamber. The housing is configured to direct the first air flow from the vacant section to the heating section to combine with the second air flow and configured to direct the first air flow and the second air flow across the heating coil.

BACKGROUND

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure and are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be noted that these statements are to be read in this light, and not as admissions of prior art.

Heating, ventilation, and air conditioning (HVAC) systems are utilized to control environmental properties, such as temperature and humidity, for occupants of residential, commercial, and industrial environments. The HVAC systems may control the environmental properties through control of an air flow delivered to the environment. For example, an HVAC system may include one or more blowers configured to generate an airflow and one or more heat exchanger coils, such as a heat exchanger coil configured to place the air flow in a heat exchange relationship with a refrigerant of a vapor compression circuit, a heat exchanger coil configured to place the air flow in a heat exchange relationship with combustion products, or other heat exchanger configured to transfer heat to and/or from the air flow. In traditional systems, heat exchange coils may be oriented in a manner that causes uneven conditioning of an air flow directed across the heat exchange coils. Further, existing heat exchanger coil orientations may limit operation and/or reduce efficiency of HVAC systems. Accordingly, it is now recognized that improved heat exchanger coil orientations for HVAC units is desired.

SUMMARY

A summary of certain embodiments disclosed herein is set forth below. It should be noted that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

In one embodiment, a heating, ventilation, and air conditioning (HVAC) system comprises a housing defining a chamber configured to receive a first air flow and a second air flow. The chamber comprises a vacant section and a heating section, and the heating section comprises a heating coil. A first blower is configured to direct the first air flow into the vacant section of the chamber and a second blower is configured to direct the second air flow into the heating section of the chamber. The housing is configured to direct the first air flow from the vacant section to the heating section to combine with the second air flow and configured to direct the first air flow and the second air flow across the heating coil.

In another embodiment, a heating, ventilation, and air conditioning (HVAC) system comprises a housing defining a chamber. A first airflow path extends from a first blower, through an open section of the chamber, and through a heating section of the chamber to a discharge outlet of the housing, a second airflow path extends from a second blower through the heating section of the chamber to the discharge outlet of the housing, and a heating coil is disposed within the heating section.

In a further embodiment, a heating system of a heating, ventilation, and air conditioning (HVAC) system comprises a housing defining a chamber comprising a vacant section and a heating section, and a heating coil disposed within the heating section. The housing further comprises a first inlet configured to direct a first air flow into the vacant section and a second inlet configured to direct a second air flow into the heating section. The housing is configured to direct the first air flow from the vacant section to the heating section to combine the first airflow with the second air flow and configured to direct the first air flow and the second air flow across the heating coil.

BRIEF DESCRIPTION OF DRAWINGS

Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:

FIG. 1 is a perspective view of a building having an embodiment of a heating, ventilation, and air conditioning (HVAC) system for environmental management that may employ one or more HVAC units, in accordance with an aspect of the present disclosure;

FIG. 2 is a perspective view of an embodiment of a packaged HVAC unit that may be used in the HVAC system of FIG. 1 , in accordance with an aspect of the present disclosure;

FIG. 3 is a cutaway perspective view of an embodiment of a residential, split HVAC system, in accordance with an aspect of the present disclosure;

FIG. 4 is a schematic illustration of an embodiment of a vapor compression system that may be used in any of the systems of FIGS. 1-3 , in accordance with an aspect of the present disclosure;

FIG. 5 is a perspective view of an embodiment of an HVAC unit, in accordance with an aspect of the present disclosure;

FIG. 6 is a cross-sectional, schematic side view of an embodiment of a heating system, in accordance with an aspect of the present disclosure;

FIG. 7 is a partial cross-sectional, schematic side view of an embodiment of a heating section of a heating system, in accordance with an aspect of the present disclosure;

FIG. 8 is a perspective view of an embodiment of a heating system, in accordance with an aspect of the present disclosure;

FIG. 9A is a perspective view of an embodiment of an HVAC unit having an end-return configuration, in accordance with an aspect of the present disclosure; and

FIG. 9B is a perspective view of an embodiment of an HVAC unit having a side-return configuration, in accordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be noted that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be noted that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be noted that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

The present disclosure is directed to a heating, ventilation, and/or air conditioning (HVAC) system having a heat exchanger (e.g., a heat exchange coil) configured to condition an air flow directed through the HVAC system. For example, the heat exchanger may be configured to heat, cool, dehumidify, or otherwise adjust a parameter of the air flow as the air flow is directed across the heat exchanger. In some embodiments, the heat exchanger may be disposed in a packaged outdoor unit or a rooftop unit configured to both heat and cool an air flow, such as a supply air flow that is conditioned and directed to a conditioned space (e.g., a building). For example, the heat exchanger may be an electric heating coil configured to convert electrical energy passing therethrough into thermal energy. In other embodiments, the heat exchanger may be a furnace having heat exchange tubes configured to receive relatively hot combustion products (e.g., combusted flue gas) generated via a burner assembly, or the heat exchanger may be a coil disposed along a vapor compression circuit that is configured to circulate a working fluid (e.g., a refrigerant) therethrough and place the air flow in a heat exchange relationship with the working fluid. Indeed, the HVAC system may include multiple heat exchangers (e.g., heat exchanger coils) configured to exchange heat with one or more air flows directed through the HVAC system. The HVAC system may also include one or more blowers configured to direct a supply air flow across one of the heat exchangers, thereby placing the supply air flow in a heat exchange relationship with the heat exchangers to condition (e.g., heat, cool, dehumidify) the supply air flow.

As noted above, heat exchangers may be disposed within various HVAC systems, such as a rooftop unit, a packaged unit, or other HVAC unit housing. In some embodiments, an HVAC unit housing may be arranged in a side-flow configuration (e.g., side-flow discharge configuration) that is configured to discharge a supply air flow through a discharge outlet formed in a lateral side (e.g., in a direction along a horizontal axis) of the HVAC unit housing after the supply air flow is conditioned by the HVAC system. The supply air flow discharged from the HVAC unit housing may then be directed to a conditioned space via ductwork, for example. In traditional systems employing a side-flow configuration, multiple heat exchange coils may be disposed within a housing of the HVAC unit, and each heat exchange coil may be associated with a respective blower. For example, each blower may be positioned above a corresponding heat exchange coil relative to gravity. As the HVAC system operates, each blower may direct an air flow across the corresponding heat exchange coil to condition the air flow before the air flow is directed out of a lateral side of the HVAC unit housing and toward the conditioned space. It is now recognized that traditional systems employing a side-flow configuration provide inefficient conditioning and/or uneven conditioning (e.g., overheating) of a supply air flow that is conditioned by the HVAC system and directed to a conditioned space. For example, existing designs may include a first heat exchange coil positioned upstream of a second heat exchange coil relative to a direction of air flow through the HVAC unit housing and across the heat exchange coils. As the one or more air flows are directed across the heat exchange coils and towards the discharge outlet (e.g., supply air outlet) disposed on the lateral side of the HVAC unit housing, at least a portion of the supply air flow may be conditioned by the first heat exchange coil and then conditioned again by the second heat exchange coil, thereby causing the supply air flow to be over conditioned (e.g., overheated, unevenly conditioned). Furthermore, traditional systems may utilize multiple blowers of a common size. For example, blowers may be the same size in existing systems where each blower is associated with a respective heat exchange coil, and each heat exchange coil is the same size. In such systems, the air flows generated by the multiple blowers may be combined and discharged via a common or single outlet of the HVAC unit housing. For example, a first air flow directed across a first heat exchange coil may be directed to combine with a second air flow directed across a second heat exchange coil, and the combined air flows may be discharged from the HVAC unit housing as the supply air flow. As a result, the first air flow may experience a drop in pressure as the first air flow is directed through the HVAC unit housing, thereby limiting an efficiency of the HVAC system.

Accordingly, it is now recognized that improved positioning and orientation of heat exchange coils in HVAC systems employing a side-flow configuration, in accordance with the present disclosure, may enable improved conditioning of a supply air flow generated by the HVAC system. For example, improved positioning and orientation of heat exchange coils may reduce undesired (e.g., uneven, inefficient) conditioning of the supply air flow and may limit a pressure drop experienced by the supply air flow directed through the HVAC system towards a discharge outlet of the HVAC system. Further, the improved positioning of the heat exchange coils may enable utilization of blowers within the HVAC system that have different sizes and/or configurations. In this way, improved positioning and orientation of heat exchange coils may increase the flexibility and efficiency of HVAC systems. As discussed in further detail below, an HVAC system in accordance with the present techniques may include a housing configured to support a blower assembly having a first blower and a second blower. The housing may also include a first heat exchange coil and a second heat exchange coil arranged together (e.g., in a grouped configuration) and positioned at a lateral end or side of the housing proximate a discharge outlet of the housing. The first and second blowers may be configured to direct one or more air flows across the first and second heat exchange coils such that one or more air flows may be conditioned by the first and second heat exchange coils before the air flows are discharged from the housing as a supply air flow and are directed to a conditioned space.

Turning now to the drawings, FIG. 1 illustrates a heating, ventilation, and air conditioning (HVAC) system for building environmental management that may employ one or more HVAC units. As used herein, an HVAC system includes any number of components configured to enable regulation of parameters related to climate characteristics, such as temperature, humidity, air flow, pressure, air quality, and so forth. For example, an “HVAC system” as used herein is defined as conventionally understood and as further described herein. Components or parts of an “HVAC system” may include, but are not limited to, all, some of, or individual parts such as a heat exchanger, a heater, an air flow control device, such as a fan, a sensor configured to detect a climate characteristic or operating parameter, a filter, a control device configured to regulate operation of an HVAC system component, a component configured to enable regulation of climate characteristics, or a combination thereof. An “HVAC system” is a system configured to provide such functions as heating, cooling, ventilation, dehumidification, pressurization, refrigeration, filtration, or any combination thereof. The embodiments described herein may be utilized in a variety of applications to control climate characteristics, such as residential, commercial, industrial, transportation, or other applications where climate control is desired.

In the illustrated embodiment, a building 10 is air conditioned by a system that includes an HVAC unit 12. The building 10 may be a commercial structure or a residential structure. As shown, the HVAC unit 12 is disposed on the roof of the building 10; however, the HVAC unit 12 may be located in other equipment rooms or areas adjacent the building 10. The HVAC unit 12 may be a single package unit containing other equipment, such as a blower, integrated air handler, and/or auxiliary heating unit. In other embodiments, the HVAC unit 12 may be part of a split HVAC system, such as the system shown in FIG. 3 , which includes an outdoor HVAC unit 58 and an indoor HVAC unit 56.

The HVAC unit 12 is an air cooled device that implements a refrigeration cycle to provide conditioned air to the building 10. Specifically, the HVAC unit 12 may include one or more heat exchangers across which an air flow is passed to condition the air flow before the air flow is supplied to the building. In the illustrated embodiment, the HVAC unit 12 is a rooftop unit (RTU) that conditions a supply air stream, such as environmental air and/or a return air flow from the building 10. After the HVAC unit 12 conditions the air, the air is supplied to the building 10 via ductwork 14 extending throughout the building 10 from the HVAC unit 12. For example, the ductwork 14 may extend to various individual floors or one or more zones (101, 102, 103) of the building 10 and each zone may further comprise one or more outdoor air hoods equipped with filters. In certain embodiments, the HVAC unit 12 may be a heat pump that provides both heating and cooling to the building with one refrigeration circuit configured to operate in different modes. In other embodiments, the HVAC unit 12 may include one or more refrigeration circuits for cooling an air stream and a furnace for heating the air stream.

A control device 16, one type of which may be a thermostat, may be used to designate the temperature of the conditioned air. The control device 16 also may be used to control the flow of air through the ductwork 14. For example, the control device 16 may be used to regulate operation of one or more components of the HVAC unit 12 or other components, such as dampers and fans, within the building 10 that may control flow of air through and/or from the ductwork 14. In some embodiments, other devices may be included in the system, such as pressure and/or temperature transducers or switches that sense the temperatures and pressures of the supply air, return air, and so forth. Moreover, the control device 16 may include computer systems that are integrated with or separate from other building control or monitoring systems, and even systems that are remote from the building 10.

FIG. 2 is a perspective view of an embodiment of the HVAC unit 12. In the illustrated embodiment, the HVAC unit 12 is a single package unit that may include one or more independent refrigeration circuits and components that are tested, charged, wired, piped, and ready for installation. The HVAC unit 12 may provide a variety of heating and/or cooling functions, such as cooling only, heating only, cooling with electric heat, cooling with dehumidification, cooling with gas heat, or cooling with a heat pump. As described above, the HVAC unit 12 may directly cool and/or heat an air stream provided to the building 10 to condition a space in the building 10.

As shown in the illustrated embodiment of FIG. 2 , a cabinet 24 encloses the HVAC unit 12 and provides structural support and protection to the internal components from environmental and other contaminants. In some embodiments, the cabinet 24 may be constructed of galvanized steel and insulated with aluminum foil faced insulation. Rails 26 may be joined to the bottom perimeter of the cabinet 24 and provide a foundation for the HVAC unit 12. In certain embodiments, the rails 26 may provide access for a forklift and/or overhead rigging to facilitate installation and/or removal of the HVAC unit 12. In some embodiments, the rails 26 may fit onto “curbs” on the roof to enable the HVAC unit 12 to provide air to the ductwork 14 from the bottom of the HVAC unit 12 while blocking elements such as rain from leaking into the building 10.

The HVAC unit 12 includes heat exchangers 28 and 30 in fluid communication with one or more refrigeration circuits. Tubes within the heat exchangers 28 and 30 may circulate refrigerant, such as R-410A, through the heat exchangers 28 and 30. The tubes may be of various types, such as multichannel tubes, conventional copper or aluminum tubing, and so forth. Together, the heat exchangers 28 and 30 may implement a thermal cycle in which the refrigerant undergoes phase changes and/or temperature changes as it flows through the heat exchangers 28 and 30 to produce heated and/or cooled air. For example, the heat exchanger 28 may function as a condenser where heat is released from the refrigerant to ambient air, and the heat exchanger 30 may function as an evaporator where the refrigerant absorbs heat to cool an air stream. In other embodiments, the HVAC unit 12 may operate in a heat pump mode where the roles of the heat exchangers 28 and 30 may be reversed. That is, the heat exchanger 28 may function as an evaporator and the heat exchanger 30 may function as a condenser. In further embodiments, the HVAC unit 12 may include a furnace for heating the air stream that is supplied to the building 10. While the illustrated embodiment of FIG. 2 shows the HVAC unit 12 having two of the heat exchangers 28 and 30, in other embodiments, the HVAC unit 12 may include one heat exchanger or more than two heat exchangers.

The heat exchanger 30 is located within a compartment 31 that separates the heat exchanger 30 from the heat exchanger 28. Fans 32 draw air from the environment through the heat exchanger 28. Air may be heated and/or cooled as the air flows through the heat exchanger 28 before being released back to the environment surrounding the HVAC unit 12. A blower assembly 34, powered by a motor 36, draws air through the heat exchanger 30 to heat or cool the air. The heated or cooled air may be directed to the building 10 by the ductwork 14, which may be connected to the HVAC unit 12. Before flowing through the heat exchanger 30, the conditioned air flows through one or more filters 38 that may remove particulates and contaminants from the air. In certain embodiments, the filters 38 may be disposed on the air intake side of the heat exchanger 30 to prevent contaminants from contacting the heat exchanger 30.

The HVAC unit 12 also may include other equipment for implementing the thermal cycle. Compressors 42 increase the pressure and temperature of the refrigerant before the refrigerant enters the heat exchanger 28. The compressors 42 may be any suitable type of compressors, such as scroll compressors, rotary compressors, screw compressors, or reciprocating compressors. In some embodiments, the compressors 42 may include a pair of hermetic direct drive compressors arranged in a dual stage configuration 44. However, in other embodiments, any number of the compressors 42 may be provided to achieve various stages of heating and/or cooling. Additional equipment and devices may be included in the HVAC unit 12, such as a solid-core filter drier, a drain pan, a disconnect switch, an economizer, pressure switches, phase monitors, and humidity sensors, among other things.

The HVAC unit 12 may receive power through a terminal block 46. For example, a high voltage power source may be connected to the terminal block 46 to power the equipment. The operation of the HVAC unit 12 may be governed or regulated by a control board 48. The control board 48 may include control circuitry connected to a thermostat, sensors, and alarms. One or more of these components may be referred to herein separately or collectively as the control device 16. The control circuitry may be configured to control operation of the equipment, provide alarms, and monitor safety switches. Wiring 49 may connect the control board 48 and the terminal block 46 to the equipment of the HVAC unit 12.

FIG. 3 illustrates a residential heating and cooling system 50, also in accordance with present techniques. The residential heating and cooling system 50 may provide heated and cooled air to a residential structure, as well as provide outside air for ventilation and provide improved indoor air quality (IAQ) through devices such as ultraviolet lights and air filters. In the illustrated embodiment, the residential heating and cooling system 50 is a split HVAC system. In general, a residence 52 conditioned by a split HVAC system may include refrigerant conduits 54 that operatively couple the indoor unit 56 to the outdoor unit 58. The indoor unit 56 may be positioned in a utility room, an attic, a basement, and so forth. The outdoor unit 58 is typically situated adjacent to a side of residence 52 and is covered by a shroud to protect the system components and to prevent leaves and other debris or contaminants from entering the unit. The refrigerant conduits 54 transfer refrigerant between the indoor unit 56 and the outdoor unit 58, typically transferring primarily liquid refrigerant in one direction and primarily vaporized refrigerant in an opposite direction.

When the system shown in FIG. 3 is operating as an air conditioner, a heat exchanger 60 in the outdoor unit 58 serves as a condenser for re-condensing vaporized refrigerant flowing from the indoor unit 56 to the outdoor unit 58 via one of the refrigerant conduits 54. In these applications, a heat exchanger 62 of the indoor unit functions as an evaporator. Specifically, the heat exchanger 62 receives liquid refrigerant, which may be expanded by an expansion device, and evaporates the refrigerant before returning it to the outdoor unit 58.

The outdoor unit 58 draws environmental air through the heat exchanger 60 using a fan 64 and expels the air above the outdoor unit 58. When operating as an air conditioner, the air is heated by the heat exchanger 60 within the outdoor unit 58 and exits the unit at a temperature higher than it entered. The indoor unit 56 includes a blower or fan 66 that directs air through or across the indoor heat exchanger 62, where the air is cooled when the system is operating in air conditioning mode. Thereafter, the air is passed through ductwork 68 that directs the air to the residence 52. The overall system operates to maintain a desired temperature as set by a system controller. When the temperature sensed inside the residence 52 is higher than the set point on the thermostat, or the set point plus a small amount, the residential heating and cooling system 50 may become operative to refrigerate additional air for circulation through the residence 52. When the temperature reaches the set point, or the set point minus a small amount, the residential heating and cooling system 50 may stop the refrigeration cycle temporarily.

The residential heating and cooling system 50 may also operate as a heat pump. When operating as a heat pump, the roles of heat exchangers 60 and 62 are reversed. That is, the heat exchanger 60 of the outdoor unit 58 will serve as an evaporator to evaporate refrigerant and thereby cool air entering the outdoor unit 58 as the air passes over the outdoor heat exchanger 60. The indoor heat exchanger 62 will receive a stream of air blown over it and will heat the air by condensing the refrigerant.

In some embodiments, the indoor unit 56 may include a furnace system 70. For example, the indoor unit 56 may include the furnace system 70 when the residential heating and cooling system 50 is not configured to operate as a heat pump. The furnace system 70 may include a burner assembly and heat exchanger, among other components, inside the indoor unit 56. Fuel is provided to the burner assembly of the furnace system 70 where it is mixed with air and combusted to form combustion products. The combustion products may pass through tubes or piping in a heat exchanger, separate from heat exchanger 62, such that air directed by the blower or fan 66 passes over the tubes or pipes and extracts heat from the combustion products. The heated air may then be routed from the furnace system 70 to the ductwork 68 for heating the residence 52.

FIG. 4 is an embodiment of a vapor compression system 72 that can be used in any of the systems described above. The vapor compression system 72 may circulate a refrigerant through a circuit starting with a compressor 74. The circuit may also include a condenser 76, an expansion valve(s) or device(s) 78, and an evaporator 80. The vapor compression system 72 may further include a control panel 82 that has an analog to digital (A/D) converter 84, a microprocessor 86, a non-volatile memory 88, and/or an interface board 90. The control panel 82 and its components may function to regulate operation of the vapor compression system 72 based on feedback from an operator, from sensors of the vapor compression system 72 that detect operating conditions, and so forth.

In some embodiments, the vapor compression system 72 may use one or more of a variable speed drive (VSDs) 92, a motor 94, the compressor 74, the condenser 76, the expansion valve or device 78, and/or the evaporator 80. The motor 94 may drive the compressor 74 and may be powered by the variable speed drive (VSD) 92. The VSD 92 receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor 94. In other embodiments, the motor 94 may be powered directly from an AC or direct current (DC) power source. The motor 94 may include any type of electric motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.

The compressor 74 compresses a refrigerant vapor and delivers the vapor to the condenser 76 through a discharge passage. In some embodiments, the compressor 74 may be a centrifugal compressor. The refrigerant vapor delivered by the compressor 74 to the condenser 76 may transfer heat to a fluid passing across the condenser 76, such as ambient or environmental air 96. The refrigerant vapor may condense to a refrigerant liquid in the condenser 76 as a result of thermal heat transfer with the environmental air 96. The liquid refrigerant from the condenser 76 may flow through the expansion device 78 to the evaporator 80.

The liquid refrigerant delivered to the evaporator 80 may absorb heat from another air stream, such as a supply air stream 98 provided to the building 10 or the residence 52. For example, the supply air stream 98 may include ambient or environmental air, return air from a building, or a combination of the two. The liquid refrigerant in the evaporator 80 may undergo a phase change from the liquid refrigerant to a refrigerant vapor. In this manner, the evaporator 80 may reduce the temperature of the supply air stream 98 via thermal heat transfer with the refrigerant. Thereafter, the vapor refrigerant exits the evaporator 80 and returns to the compressor 74 by a suction line to complete the cycle.

In some embodiments, the vapor compression system 72 may further include a reheat coil in addition to the evaporator 80. For example, the reheat coil may be positioned downstream of the evaporator relative to the supply air stream 98 and may reheat the supply air stream 98 when the supply air stream 98 is overcooled to remove humidity from the supply air stream 98 before the supply air stream 98 is directed to the building 10 or the residence 52.

It should be appreciated that any of the features described herein may be incorporated with the HVAC unit 12, the residential heating and cooling system 50, or other HVAC systems. Additionally, while the features disclosed herein are described in the context of embodiments that directly heat and cool a supply air stream provided to a building or other load, embodiments of the present disclosure may be applicable to other HVAC systems as well. For example, the features described herein may be applied to mechanical cooling systems, free cooling systems, chiller systems, or other heat pump or refrigeration applications.

As briefly discussed above, embodiments of the present disclosure are directed to an HVAC system having at least one heat exchange coil positioned proximate a discharge outlet (e.g., supply air discharge, supply air opening, etc.) of the HVAC system and configured to condition one or more air flows directed across the at least one heat exchange coil. For example, a first air flow directed by a first blower and a second air flow directed by a second blower may be directed across the heat exchange coil to generate a supply air flow discharged from the HVAC system via the discharge outlet. In some embodiments, the at least one heat exchange coil may be a heating coil (e.g., an electric heating coil) configured to increase a temperature of the air flows to generate a heated supply air flow. However, it should be appreciated that the presently disclosed techniques may be utilized by any of the systems described or illustrated in FIGS. 1-4 , as well as other HVAC systems, to improve conditioning of air flows (e.g., provide more even condoning of the air flows) and to enable improved configurability of the HVAC system, such as via accommodation of different blower sizes and configurations. Indeed, the presently disclosed techniques may be utilized with heat exchange coils configured to heat, cool, dehumidify, and/or otherwise condition air flows directed through the HVAC system.

In accordance with the present disclosure, an HVAC system may include a heating assembly (e.g., heating system, electric heater, heating coil) configured to heat one or more air flows directed through the HVAC system and across the heating assembly. For example, the HVAC system may be configured to generate a first air flow and a second air flow to be conditioned via the heating assembly. The HVAC system may include a housing (e.g., a chamber, an enclosure) defining a blower section having a first blower configured to generate the first air flow and a second blower configured to generate the second air flow. The housing may also define a discharge or supply air section having the heater assembly. In particular, the supply air section may include a vacant section (e.g., vacant region, vacant portion) and a heating section (e.g., heating region, heating portion), and the heating assembly may be disposed in the heating section of the supply air section. The first air flow may be directed into a vacant section of the supply air section by the first blower, and the second air flow may be directed into the heating section of the supply air section by the second blower. The first and second air flows may be combined within the supply air section to generate a supply air flow (e.g., a combined air flow), and the supply air flow may be directed across the heating assembly to condition the supply air flow. The supply air flow may then be discharged from the supply air section via a discharge outlet formed in the housing (e.g., in a lateral side of the housing). As discussed further below, the positioning of the heating assembly downstream of the first blower and the second blower enables the combined supply air flow to be directed across a heat exchange coil of the heating assembly. In other words, the first air flow and/or the second air flow may not be directed across multiple heat exchange coils. In this way, uneven conditioning of the first air flow, the second air flow, or both is reduced. Further, HVAC systems incorporating the present techniques may not include baffles or deflectors that are typically incorporated in existing systems having separate heat exchange coils associated with separate blowers, which may reduce a pressure drop induced in the air flows, thereby increasing the efficiency of the HVAC system.

With this in mind, FIG. 5 is a perspective view of an embodiment of an HVAC unit 100 (e.g., rooftop unit, air handling unit, HVAC system) that may employ the heating assembly (e.g., heating system) disclosed herein. The HVAC unit 100 may be or include any suitable HVAC system and/or HVAC system components, such as the HVAC unit 12, the residential heating and cooling system 50, and/or any of the components described above. In the illustrated embodiment, the HVAC unit 100 includes multiple components enclosed within an internal volume of a housing 102 of the HVAC unit 100. The HVAC unit 100 may be configured to circulate air via a blower assembly 104 having a first blower 106 and a second blower 108 disposed within a blower section 109 of the housing 102. That is, the blower assembly 104 may be configured to direct (e.g., force, draw) an air flow (e.g., air flow 101) along an air flow path 107 through the housing 102 of the HVAC unit 100. For example, the HVAC unit 100 may include a return air section 110 configured to receive an air flow, such as a return air flow from the building 10 of FIG. 1 , and a supply air section 112 (e.g., discharge section) configured to output or discharge a supply air flow 113 conditioned by the HVAC unit 100. In the illustrated embodiment, the housing 102 includes a discharge outlet 111 formed in a lateral side 103 of the housing 102 to enable discharge of the supply air flow 113 from the supply air section 112 in a direction along a longitudinal axis 180 (e.g., horizontal axis). Thus, the configuration of the HVAC unit 100 may be referred to as a side flow or side discharge configuration.

During operation, the blower assembly 104 may draw an air flow (e.g., air flow 101) into the return air section 110 of the HVAC unit 100 and direct the air flow into the supply air section 112, from which the air flow may be discharged as the supply air flow 113 toward a conditioned space. In other words, the air flow path 107 of the HVAC unit 100 may be defined at least partially by the return air section 110, the blower section 109, and the supply air section 112. As an example, the HVAC unit 100 may be installed in an outdoor or ambient environment, such as on a rooftop of a building, and may be coupled to ductwork that directs air to and/or from rooms or other areas within the building. Ductwork may be fluidly coupled to the return air section 110 to direct a return air flow into the HVAC unit 100, and ductwork may be fluidly coupled to the supply air section 112 to receive the supply air flow 113 from the HVAC unit 100. In this manner, the blower assembly 104 may circulate air through the HVAC unit 100 and a conditioned space. It should be appreciated that the HVAC unit 100 may additionally or alternatively be configured to receive and/or discharge other air flows. For example, the HVAC unit 100 may be configured to receive an air flow from an outdoor environment (e.g., an ambient air flow), to discharge an air flow to the outdoor embodiment (e.g., discharge return air flow as an exhaust air flow), and so forth. In some embodiments, the HVAC unit 100 may combine a return air flow and an ambient air flow to generate the supply air flow 113. Accordingly, the air flow 101 illustrated in FIG. 5 may be a return air flow, an ambient air flow, or a combination thereof.

In addition to circulating air through the housing 102, the HVAC unit 100 may be configured to adjust one or more operating parameters of the one or more air flows directed therethrough. For example, the HVAC unit 100 may be configured to adjust a temperature, pressure, humidity, particle content, or other operating parameter of an air flow directed therethrough. Indeed, the HVAC unit 100 may operate in multiple different operating modes, such as a cooling mode, a heating mode, a dehumidification mode, and so forth. In some embodiments, the HVAC unit 100 may include a refrigerant circuit (e.g., vapor compression system 72) configured to circulate a refrigerant therethrough, and the refrigerant circuit may be placed in thermal communication with one or more air flows directed through the HVAC unit 100. In particular, the refrigerant circuit may include one or more heat exchangers configured to place the refrigerant in thermal communication with one or more of the air flows to adjust an operating parameter of supply air flow 113. The illustrated embodiment of the HVAC unit 100 includes an evaporator coil 114 configured to circulate refrigerant therethrough to absorb heat from one or more air flows directed across the evaporator coil 114, thereby reducing a temperature of the one or more air flows, in a cooling mode of the HVAC unit 100. Thus, the refrigerant within the evaporator coil 114 may be heated as the one or more air flows are directed across the evaporator coil 114. In the illustrated embodiment, the evaporator coil 114 is positioned downstream of the return air section 110 and upstream of the blower section 109 relative to a direction of the air flow 101 along the air flow path 107. Accordingly, the blower assembly 104 may operate to draw an air flow from the return air section 110, across the evaporator coil 114, and into the blower section 109.

The HVAC unit 100 may also be configured to increase a temperature of one or more air flows directed through the HVAC unit 100 in a heating operating mode. Thus, the supply air flow 113 may be discharged by the HVAC unit 100 to heat a conditioned space. To this end, the HVAC unit 100 includes a heating assembly 116 including a heat exchanger 120 (e.g., heating coil, heater, electric heating coil) configured to transfer thermal energy to one or more air flows directed through the HVAC unit 100. In some embodiments, the heat exchanger 120 may be an electric heating coil coupled to a power source and configured to convert electrical energy to thermal energy. However, in other embodiments, the heat exchanger 120 may be configured to circulate a heated working fluid (e.g., refrigerant, water, combustion products) therethrough. For example, the heat exchanger 120 may be a furnace.

In the illustrated embodiment, the heating assembly 116 is disposed within the supply air section 112 of the HVAC unit 100. Thus, during a heating mode of the HVAC unit 100, the blower assembly 104 may direct multiple air flows into the supply air section 112, and the multiple air flows may be combined within the supply air section 112 and directed across or through the heating assembly 116. In other words, the combined air flow may be directed across the heat exchanger 120. In accordance with the present techniques, the heat exchanger 120 is positioned within the supply air section 112 downstream of first blower 106 (e.g., relative to a first direction of an air flow generated by the first blower 106 along the air flow path 107) and downstream of the second blower 108 (e.g., relative to a second direction of an air flow generated by the second blower 108 along the air flow path 107). By positioning the heat exchanger 120 downstream of the first and second blowers 106, 108 within the supply air section 112, respective air flows directed into the supply air section 112 may be combined upstream of the heat exchanger 120 and directed across the heat exchanger 120 as a combined air flow. In this way, the combined air flow (e.g., the respective air flows induced by the first and second blowers 106, 108) is heated once as the air flow is directed across the heat exchanger 120 (e.g., a single heat exchanger or heating coil), which may reduce undesired or uneven heating (e.g., overheating) of the multiple air flows directed into the supply air section 112 by the blower assembly 104. While the heat exchanger 120 is described as a single heat exchanger or heating coil, in some embodiments, the heat exchanger 120 may be a grouped heat exchanger having two, three, four or more heating coils arranged in a stacked orientation such that each heat exchange coil is positioned above or below another of the heat exchange coils relative to gravity. Further, by utilizing the heat exchanger 120 positioned downstream of the first and second blowers 106, 108 to heat the combined air flow, the HVAC unit 100 (e.g., the supply air section 112) may not include components typically included in existing systems that may obstruct air flow through the supply air section 112 (e.g., deflectors). Thus, pressure drop of the air flows directed into the supply air section is reduced and efficiency of the HVAC unit 100 is increased. Further still, the heat exchanger 120 positioned downstream of the first and second blowers 106, 108 enables implementation of different blower sizes in the blower assembly 104. That is, the first and second blowers 106, 108 may be different sizes, thereby increasing the flexibility of the HVAC unit 100 to provide different components, configurations, capacities, operations, and so forth. The features and aspects of the heating assembly 116 and the heat exchanger 120 are discussed in further detail below.

FIG. 6 is a cross-sectional, schematic side view of an embodiment of a heating system 200 (e.g., heating assembly, heater) having a heat exchanger 201 (e.g., heating coil) that may be incorporated with or in any of the systems described above with reference to FIGS. 1-5 (e.g., HVAC unit 100) or any other suitable HVAC system. For example, the heating system 200 may correspond to the heating assembly 116 of FIG. 5 , and the heat exchanger 201 may correspond to the heat exchanger 120 of FIG. 5 . The heating system 200 is configured to transfer thermal energy (e.g., heat) to one or more air flows directed through a housing of an HVAC unit, such as the HVAC unit 100 of FIG. 5 . Thus, the heating system 200 enables the HVAC unit 100 to provide heated supply air flow 113. The illustrated embodiment is intended to focus on certain features that enable the functionalities and benefits of the presently disclosed techniques, but it should be appreciated that the heating system 200 may include additional features, such as one or more of the components described above with reference to FIGS. 1-5 .

The heat exchanger 201 of the heating system 200 is disposed within a housing 204 (e.g., support structure). For example, the housing 204 may be a portion of the housing 102 discussed above, and the housing 204 may define the supply air section 112. The heat exchanger 201 may be formed from multiple heating coils coupled or arranged together as a single heat exchanger. For example, the heat exchanger 201 may include a first heating coil 202 (e.g., electric heating coil) and a second heating coil 203 (e.g., electric heating coil) that are each configured to provide heat to one or more air flows directed across the heating coils 202, 203. In some embodiments, each of the heat exchange coils 202, 203 of the heat exchanger 201 may be controlled independently, thereby enabling the heating system 200 to control a heat output of the heat exchanger 201. For example, when the heating system 200 is called upon to provide a heated supply air flow 251, the first heating coil 202 may be operated while operation of the second heating coil 203 is suspended, thereby enabling the heating system 200 to limit overheating of the air flows directed across the heat exchanger 201. That is, based on a temperature difference between a desired set point temperature and a current temperature of a conditioned room, the heating system 200 may be configured to operate one of the heat exchange coils 202, 203 while operation of the other heat exchange coil is suspended, or alternatively, operate both heating coils 202, 203 of the heat exchanger 201 simultaneously to increase the amount of heat transferred to air flows directed across the heat exchanger 201.

As similarly discussed above, the housing 204 is configured to direct one or more air flows towards and across the heat exchanger 201. For example, the housing 204 may include a first side 206 (e.g., top side, panel, wall, etc.), a second side 208 (e.g., base, bottom side, panel, wall, etc.) opposite the first side 206, a third side 210 (e.g., lateral wall, side wall, side panel), a fourth side 212 (e.g., lateral wall, side wall, side panel, discharge side) opposite the third side 210, a fifth side (e.g., front side, wall, panel), and a sixth side (e.g., back side, wall, panel) opposite the fifth side. Each of the sides (e.g., sides 206, 208, 210, 212) may have an inner surface that defines a chamber 224 (e.g., plenum) of the housing 204 configured to receive one or more air flows and to direct the one or more air flows across the heat exchanger 201. In some embodiments, the housing 204 may be configured to support a blower assembly 218 (e.g., blower assembly 104) having a first blower 220 and a second blower 222 coupled (e.g., mounted) to the first side 206 of the housing 204. However, in other embodiments, the blower assembly 218 may be supported by another portion or structure of an HVAC unit having the housing 204.

The first blower 220 and the second blower 222 are each configured to direct a respective air flow into the housing 204. Specifically, the first blower 220 is configured to direct a first air flow 228 into the housing 204, and the second blower 222 is configured to direct a second air flow 236 into the housing 204. The first blower 220 may be positioned upstream of the second blower 222 relative to a direction 252 of first and second air flows 228, 236 directed through the housing 204. That is, the first and second air flows 228, 236 generated by the first and second blowers 220, 222, respectively, may be directed into the housing 204 and may travel along one or more air flow paths in the direction 252 towards a supply air outlet 250 (e.g., discharge outlet) disposed within the fourth side 212 (e.g., lateral side) of the housing 204, as described in greater detail below. The blowers 220, 222 (e.g., blower assembly 218) may be coupled or secured to the first side 206 of the housing 204 via fasteners, pins, nuts and bolts, brazes, or other suitable fastening techniques. In some embodiments, the first and second blowers 220, 222 may be the same size and be configured to output the first and second air flows 228, 236 at the same flow rate, while in other embodiments, the first and second blowers 220, 222 may be different sizes and be configured to output the first and second air flows 228, 236 at different flow rates. During operating, the heating system 200 or an HVAC unit having the heating system 200 may receive a call to provide a conditioned (e.g., heated) air flow to a conditioned space, and the blowers 220, 222 may be operated to generate or direct the first and second air flows 228, 236 into the chamber 224 and across the heat exchanger 201 to be heated by the heat exchanger 201. In some embodiments, the first and second blowers 220, 222 may be independently operated, such that the blower assembly 218 may generate the first air flow 228, the second air flow 236, or both (e.g., based on one or more operating parameters of the HVAC unit 100 having the heating system 200).

By having multiple blowers 220, 222 having different sizes and operable at different flow rates and/or speeds, hot spots on the heat exchanger 201 may be reduced as the first and second air flows 228, 236 are combined before being directed across the heat exchanger 201. For example, if an air flow is directed unevenly across a heat exchanger, hot spots on the heat exchanger may be generated as portions of the heat exchanger experience a higher volume of the air flow than other portions. By controlling the flow rate and/or speed of the blowers 220, 222, the first and second air flows 228, 236 may be directed across the heat exchanger 201 evenly, such that hot spots on the heat exchanger 201 are reduced. Further, reduced air flow rates enable higher temperature rise of a respective air flow directed across a heat exchanger, as the respective air flow contacts the heat exchanger for an increased amount of time. As such, by having blowers 220, 222 operable at different flow rates and/or speeds, the flow rate of the first and second air flows 228, 236 generated by the first and second blowers 220, 222, respectively, may be reduced and the temperature rise of the first and second air flows 228, 236 may be controlled, thereby increasing the efficiency of the heating system 200. Further still, by having blowers 220, 222 that are independently operated at various flow rates and/or speeds, the flow rates and/or speeds of the first and second air flows 228, 236 may be controlled independently, thereby enabling adjustment of the heat output of the heat exchanger 201 based on the flow rates and speeds of the first and second air flows 228, 236.

The chamber 224 defined by the housing 204 may extend a length 270 (e.g., a dimension from the third side 210 to the fourth side 212) of the housing 204 in a direction along a horizontal axis 190, and may extend a height 271 (e.g., a dimension from the first side 206 to the second side 208) of the housing 204 in a direction along a vertical axis 192. The chamber 224 may include a first section 226 (e.g., vacant section or region, unobstructed section or region, open section or region) configured to receive the first air flow 228 generated by the first blower 220. In the illustrated embodiment, the first section 226 is positioned beneath the first blower 220 (e.g., relative to the vertical axis 192), but in other embodiments the first blower 220 and the first section 226 may be arranged in other positions relative to one another. The first air flow 228 may be directed by the first blower 220 along a first air flow path 230 from the first blower 220, through the first side 206 of the housing 204 via a first inlet 232 (e.g., opening, port), and into the first section 226 of the chamber 224.

As noted above, the heating system 200 may be part of an HVAC unit 100 arranged in a side-flow configuration. In a side-flow configuration, a supply air flow generated by the HVAC unit 100 may be discharged out of a lateral side of the HVAC unit 100 (e.g., lateral side 103 of HVAC unit 100). The housing 204 in the illustrated embodiment is arranged in a side-flow configuration with the fourth side 212 of the housing 204 having the supply air outlet 250 formed therein. Thus, the housing 204 is configured to discharge air flow via a lateral side of the housing 204. Accordingly, upon entering the first section 226 of the chamber 224, the first air flow 228 may contact one or more of the inner surfaces of the housing 204, and the housing 204 may direct the first air flow 228 along the first air flow path 230 in the direction 252 (e.g., horizontal direction) along the horizontal axis 190 towards the heat exchanger 201 and the supply air outlet 250 (e.g., discharge outlet) formed in the fourth side 212 (e.g., lateral side) of the housing 204. The first section 226 of the chamber 224 may not include a heat exchanger disposed therein and may therefore be generally vacant. In other words, the first section 226 may define an unobstructed section or portion of the first air flow path 230 that generally does not impede flow of the first air flow 228 through the housing 204. Indeed, by enabling the first air flow 228 to flow through the first air flow path 230 generally unobstructed, air flow directed through the chamber

Further, the chamber 224 may include a second section 234 (e.g., heat exchanger section or region, heating section or region) configured to receive the second air flow 236 generated by the second blower 222. As shown, the second section 234 is positioned beneath the second blower 222 (e.g., relative to the vertical axis 192), but in other embodiments the second blower 222 and the second section 234 may be arranged in other positions relative to one another. The second air flow 236 may be directed by the second blower 222 along a second air flow path 238 from the second blower 222, through the first side 206 of the housing 204 via a second inlet 240 (e.g., opening, port), and into the second section 234 of the chamber 224. Additionally, the heat exchanger 201 may be positioned within the second section 234 of the chamber 224. For example, the heat exchanger 201 may be positioned proximate or adjacent the fourth side 212 of the housing 204 and the supply outlet 250. By positioning the heat exchanger 201 proximate the fourth side 212 of the housing 204 and the supply air outlet 250, overheating of the first air flow 228 may be reduced, and more even heating of the first and second air flows 228, 236 may be achieved, as described in greater detail below. Further, by enabling the first air flow 228 to flow through the first air flow path 230 generally unobstructed, air flows 228, 236 may be more evenly distributed throughout the chamber 224, thereby facilitating positioning of sensors 255 configured to collect data associated with the first and second air flows 228, 236. That is, by positioning the heat exchanger 201 proximate the supply air outlet 250 and having the first section 226 generally unobstructed, sensors 255 may be disposed within the chamber 224 without interfering with other components of the heating system 200 (e.g., heat exchanger 201), thereby enabling more reliable and accurate collected of data associated with the first and second air flows 228, 236.

As illustrated, the first air flow path 230 may extend through first section 226 (e.g., open section, vacant section) and into the second section 234. Thus, the first air flow path 230 may extend to the second air flow path 238. However, in some embodiments, the first air flow path 230 may be considered to extend from the first blower 220, through the first and second sections 226, 234, across the heat exchanger 201 and to the supply air outlet 250, while the second air flow path 238 may be considered to extend from the second blower 222, through the second section 234, and across the heat exchanger 201 to the supply air outlet 250. For example, in some embodiments, the first and second blowers 220 and 222 may be operated individually and/or separately. Accordingly, the first blower 220 may operate to direct the first air flow 228 through the housing 204 to the supply air outlet 250 while operation of the second blower 222 is suspended, and the second blower 222 may operate to direct the second air flow 236 through the housing 204 to the supply air outlet 250 while operation of the first blower 220 is suspended. In some instances, during simultaneous operation of the first blower 220 and the second blower 222, the first air flow 228 may be directed through the housing 204 to combine with the second air flow 236 in the second section 234 of the housing 204. For example, the first air flow 228 may be directed through the housing 204 to combine with the second air flow 236 within the housing 204 at a location generally upstream of the heat exchanger 201 relative to the direction 252. In this way, the first and second air flows 228, 236 may combine and/or mix with one another prior to the first and second air flows 228, 236 passing across the heat exchanger 201, thereby enabling more even heating of the first and second air flows 228, 236. For example, upon entering the second section 234 of the chamber 224, the second air flow 236 may flow along the second air flow path 238 and combine with the first air flow 228 flowing along the first air flow path 230 (e.g., to form a combined air flow 248). Each of the first and second air flows 228, 236 (e.g., the combined air flow 248) may then be directed in the direction 252 (e.g., horizontal direction) along the horizontal axis 190 toward the heat exchanger 201. However, in some instances during simultaneous operation of the first blower 220 and the second blower 222, the first and second air flows 228, 236 may at least partially flow across the heat exchanger 201 separate from one another (e.g., without fully combining or mixing upstream of the heat exchanger 201). Further, in either instance (e.g., operating the first blower 220 while operation of the second blower 222 is suspended or operating the first and second blowers 220, 222 simultaneously), reduced overheating of the first air flow 228 may be achieved by directing the first air flow 228 through the first section 226 (e.g., open section without a heating coil) and through the second section 234 (e.g., heating section) to be heated once by the heat exchanger 201.

In any case, upon flowing across the heat exchanger 201, the first and second air flows 228, 236 may be heated by the heat exchanger 201 to produce a heated supply air flow 251, and the heated supply air flow 251 may be discharged from the housing 204 via the supply air outlet 250. Thereafter, the heated supply air flow 251 may be directed to a room, building, or other conditioned space. It should be noted that, although the air flow paths 230 and 238 may generally extend through the housing 204 in the direction 252 along the horizontal axis 190 to direct air flows (e.g., first air flow 228 and second air flow 236) towards the heat exchanger 201 and the supply air outlet 250, portions of the first and second air flow paths 230, 238 may also extend in other directions, such as a direction (e.g., vertical direction) along the vertical axis 192. That is, each of the first and second air flow paths 230, 238 may be configured to direct air flows (e.g., first and second air flows 228, 236) through the chamber 224 and toward the heat exchanger 201 and the supply air outlet 250 in multiple directions. Further, by having the firs

In some embodiments, the heat exchanger 201 may have a first portion 290 (e.g., top portion, upper surface) and a second portion 292 (e.g., bottom portion, lower surface). For example, the first portion 290 may be generally arranged above the second portion 292 relative to the vertical axis 192. In some embodiments, the heat exchanger 201 may be a single heat exchange coil (e.g., heating coil) configured to transfer thermal energy to one or more air flows directed through the housing 204. In other embodiments, the heat exchanger 201 may include two or more heating coils. For example, the heat exchanger 201 may include the first coil 202 and the second coil 203 positioned above the first coil 202 relative to gravity. The one or more heating coils (e.g., heating coils 202, 203) of the heat exchanger 201 may be coupled to a power source 280 via connections 282. For example, the power source 280 may be an electric power source that enables a flow of electricity to pass through the heating coil(s) of the heat exchanger 201. The power source 280 may be disposed within a component section 284 (e.g., enclosure) of the housing 204 configured to support one or more components of the heating system 200. As one or more air flows are directed across the heat exchanger 201, heat may be transferred from the heating coil(s) of the heat exchanger 201 to the one or more air flows, thereby increasing the temperature of the air flows before the air flows are discharged via the supply air outlet 250. In some embodiments, with the first heating coil 202 and the second heating coil 203 stacked together, an amount of heat output achieved by each heating coil 202, 203 may be controlled based on respective speeds of the first and second blowers 220, 222.

The heat exchanger 201 may be disposed at an oblique angle relative to the horizontal axis 190 or relative to the direction 252 of the first and second air flows 228, 236 directed across the heat exchanger 201. In the illustrated embodiment, the first portion 290 (e.g., upper portion) of the heat exchanger 201 generally faces an upstream direction (e.g., relative to the direction 252 of the first and second air flows 228, 236 through the chamber 224), and the second portion 292 generally faces the supply air outlet 250. The heat exchanger 201 may also generally extend across and within the chamber 224 at the oblique angle between the first side 206 of the housing 204 and the second side 208 of the housing 204. In some embodiments, the heat exchanger 201 may extend a dimension (e.g., substantially an entire dimension) of the height 271 of the chamber 224. That is, the heat exchanger 201 may extend a distance 274 between the first side 206 and the second side 208 of the housing 204, and the distance 274 may be substantially the same as the height 271 of the chamber 224. Thus, the heat exchanger 201 may generally extend along the height 271 of the chamber 224, such that substantially all of the first and second air flows 228, 236 directed through the housing 204 is directed across the heat exchanger 201 prior to being discharged from the housing 204 via the supply air outlet 250. Further, the heat exchanger 201 may extend across and within the chamber 224 from the fifth side (e.g., a front side) to the sixth side (e.g., a rear side) of the housing 204, as described in greater detail below. The heat exchanger 201 may be configured to extend within and across the height 271 of the chamber 224 to limit bypass of the first and second air flows 228, 236 around the heat exchanger 201, thereby increasing the efficiency of the heating system 200.

In some embodiments, the chamber 224 may also include a baffle 242 configured to guide the first and second air flows 228, 236 across the heat exchanger 201. For example, the baffle 242 may be disposed within the chamber 224 and may extend a distance 290 along the height 271 and/or the vertical axis 192. In some embodiments, the baffle 242 may extend from the second side 208 of the housing 204 and/or may extend at an oblique angle relative to the horizontal axis 190. The baffle 242 may be configured to direct at least a portion of the first and/or second air flows 228, 236 flowing through the housing 204 towards the heat exchanger 201 such that the first and/or second air flows 228, 236 may flow across the heat exchanger 201 (e.g., instead of through a channel 294 between the second portion 292 of the heat exchanger 201 and the second side 208 of the housing 294). To this end, the baffle 242 may be positioned upstream of the channel 294 relative to the direction 252 of the first and/or second air flows 228, 236 directed through the chamber 224 and may extend the distance 290 across the channel 294, such that the baffle 242 blocks air flow through the channel 294 and directs the first and/or second air flows 228, 236 to flow across and/or through the heat exchanger 201. It should be noted that, in other embodiments, the chamber 224 may include additional baffles positioned along the first and/or second sides 206, 208 of the housing 204 and upstream of the heat exchanger 201 relative to the direction 252. The additional baffles may also be configured to block bypass of the heat exchanger 201 and to direct first and/or second air flows 228, 236 towards the heat exchanger 201.

The heating system 200 may also include a controller 296, which may be disposed within the housing 204 in some embodiments. The controller 296 may be configured to control operation of the blowers 220, 222 and/or the heat exchanger 201, such as based on one or more operating parameters of the heating system 200 and/or of an HVAC system having the heating system 200. For example, the controller 296 may receive a signal indicative of a call for operation of the HVAC unit 100 and/or heating system 200 in a cooling mode, and in response the controller 296 may suspend operation of the heat exchanger 201. Thus, the heat exchanger 201 may not operate to heat the first and/or second air flows 228, 236 directed through the housing 204. The controller 296 may also receive a signal indicative of a call for operation of the HVAC unit 100 and/or heating system 200 in a heating mode, and in response the controller 296 may operate to activate the heat exchanger 201 to enable heating of the first and/or second air flows 228, 236 directed through the housing 204. In some embodiments, the controller 296 may also be configured to control operation of the blower assembly 218 (e.g., in the cooling mode, in the heating mode). While operating in the heating mode, the controller 296 may receive a signal indicative of a desired temperature set point for a conditioned room, and the controller 296 may be configured to operate the blower assembly 218 based on the desired temperature set point. That is, the controller 296 may be configured to operate the blowers 220, 222 independently or simultaneously and at different speeds and/or capacities, thereby enabling the heating system 200 to provide the supply air flow 251 at different temperatures and volumes based a difference between the current temperature and the desired temperature set point. That is, independent and adjustable (e.g., different flow rates and/or speeds) operation of the blowers 220, 222 may enable the heating system 200 to control a heat output of the heat exchanger 201. For example, if the difference between the current temperature of a conditioned room and the desired temperature for the conditioned room is above a first threshold value, the controller 296 may operate the first and second blowers 220, 222 simultaneously and at maximum capacity to deliver the supply air flow 251 to the conditioned room. If the difference between the current temperature and the desired temperature is below the first threshold value, but above a second threshold value, the controller 296 may operate the first and second blowers 220, 222 simultaneously and at a reduced capacity to deliver the supply air flow 251 to the conditioned room. Further still, if the difference between the current temperature and the desired temperature is below the second threshold value, the controller 296 may operate the first blower 220 independently, while operation of the second blower 222 is suspended or may operate the second blower 222 while operation of the first blower 220 is suspended to deliver the supply air flow 251 to the conditioned room. Accordingly, by enabling the controller 296 to control the blowers 220, 222 flow rate and/or speed based on a desired temperature set point, efficiency of the heating system 200 may be increased as blowers 220, 222 are operated when needed. It should be appreciated that the controller 296 may be a dedicated controller of the heating system 200, a main controller of an HVAC unit having the heating system 200 (e.g., control board 48, control panel 82), a component of a control system of an HVAC system having the heating system 200, or any other suitable controller.

To facilitate control of one or more components of the heating system 200, the controller 296 may include a memory 298 with instructions stored thereon for controlling operation of the heating system 200 and components of the heating system 200. The controller 296 may also include processing circuitry 299 configured to execute instructions stored on the memory 298. For example, the processing circuitry 299 may include one or more application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more general purpose processors, or any combination thereof. Additionally, the memory 298 may include a non-transitory computer-readable medium that may include volatile memory, such as random-access memory (RAM), and/or non-volatile memory, such as read-only memory (ROM), optical drives, hard disc drives, solid-state drives, or any other suitable non-transitory computer-readable medium storing instructions that, when executed by the processing circuitry 299, may control operation of the heating system 200. Although FIG. 6 illustrates the controller 296 as being disposed within the housing 204, in some embodiments, the controller 296 may be disposed elsewhere, such as remote from the heating system 200.

FIG. 7 is a schematic side view of an embodiment of a portion of the heating system 200, illustrating the second section 234 (e.g., heating section), in accordance with an aspect of the present disclosure. As noted above, one or more air flows (e.g., first and second air flows 228, 236) may be directed along air flow paths 230, 238 through the chamber 224 towards the heat exchanger 201 and the supply air outlet 250. Though the chamber 224 is configured to generally direct the air flows 228, 236 in the direction 252 towards the heat exchanger 201 and the supply air outlet 250, portions of the air flows 228, 236 may be directed in a direction 254 along the vertical axis 192. For example, upon being discharged from the second blower 222 into the chamber 224, the second air flow 236 may travel in the direction 254 through the second inlet 240 (e.g., toward the first air flow path 230). Upon reaching the first flow path 230, portions of the second air flow 236 may be forced in the direction 252 by the first air flow 228. However, other portions of the second air flow 236 may continue traveling in the direction 254 towards the second side 208 of the housing 204. Accordingly, in some embodiments, the heat exchanger 201 may be disposed at an oblique angle 300 (e.g., relative to the direction 252) and may include a first portion 205 at least partially aligned with the second blower 222 and/or the second inlet 240 (e.g., relative to the direction 254 and/or along the vertical axis 192) and a second portion 207 at least partially offset from the second blower 222 and/or second inlet 240. Thus, the first portion 205 is upstream of the second portion 207 relative to air flow in the direction 252, and the second portion 207 is more proximate the supply air outlet 250 than the first portion 205. In some instances, the first portion 205 may be configured to heat portions of the second air flow 236 initially flowing from the second blower 220 in the direction 254, and the second portion 207 may be configured to heat other portions of the first and second air flows 228, 236 traveling in the direction 252 towards the supply outlet 250. In this way, the heat exchanger 201 may be arranged within the chamber 224 to provide heating to the first and second air flows 228, 236 flowing in different directions and/or in different regions within the chamber 224, thereby enabling more even heating of the first and second air flows 228, 236 directed through the housing 204.

FIG. 8 is a perspective view of an embodiment of the heating system 200, in accordance with aspects of the present disclosure. As illustrated, the heating system 200 may include the housing 204 having the second side 208, the third side 210 (e.g., lateral side), the fourth side 212 (e.g., lateral side) opposite the third side 210, a fifth side 214 (e.g., back side, wall, panel), and a sixth side 216 (e.g., front side, wall, panel) opposite the fifth side 214. The first side 206 of the housing 204 is hidden for illustrative purposes. The illustrated embodiment also includes similar elements and element numbers described above. For example, the heating system 200 includes the power source 280 and connections 282 configured to provide power to various components of the heating system 200 (e.g., the heat exchanger 201) to heat one or more air flows directed across the heat exchanger 201. The power source 280 and the connections 282 may be housed within the component section 284, which may be an additional enclosure of the housing 204. For example, the component section 284 may be coupled to the third side 210 of the housing 204 via fasteners, pins, screws, or other suitable techniques.

As discussed above, the housing 204 may define the chamber 224 having the first section 226 and the second section 234. The chamber 224 may extend the length 270 from the third side 210 to the fourth side 212 of the housing 204 and may extend the height 271 from the first side 206 to the second side 208 of the housing 204. Further, the chamber 224 may extend a width 272 from the fifth side 214 to the sixth side 216. The heat exchanger 201 may be disposed within the second section 234 and positioned proximate the supply air outlet 250. The first section 226 does not include a heat exchanger disposed therein and is therefore vacant. As discussed above, the heat exchanger 201 may extend at the oblique angle 300 relative to the direction 252 of the first and second air flows 228, 236 through the chamber 224. The heat exchanger 201 may extend within and across the chamber 224 from the first side 206 to the second side 208 of the housing 204 by the distance 274. That is, the heat exchanger 201 may generally extend across the height 271 of the chamber 224. Further, the heat exchanger 201 may extend within and across the chamber 224 by a distance 275 from the fifth side 214 to the sixth side 216 of the housing 204. For example, the heat exchanger 201 may have a first plate 310 (e.g., first support, panel, side plate) coupled to an inner surface 312 of the fifth side 214 of the housing 204 and a second plate 314 (e.g., first support, panel, side plate) coupled to an inner surface 316 of the sixth side 216 of the housing 204. In an installed configuration of the heat exchanger 201, one or more heating coils 320 of the heat exchanger 201 may extend across the chamber 224 from the first plate 310 to the second plate 314 by the distance 275. The distance 275 may be substantially similar to, or slightly less than, the width 272 and thus, the heat exchanger 201 may extend generally across the width 272 of the chamber 224. Accordingly, the heat exchanger 201 extends within and across the chamber 224, such that air flow directed through the chamber 224 towards the supply air outlet 250 may pass across the heat exchanger 204 and receive heat from the heating coil(s) 320 of the heat exchanger 201. That is, the heat exchanger 201 may be disposed at the oblique angle 300 within the chamber 224 and extend across the chamber 224 to reduce a likelihood of air flow bypassing the heat exchanger 201 (e.g., flowing around the heat exchanger 201).

As discussed above, the heating system 200 may also include the baffle 242 configured to guide one or more air flows within the chamber 224 towards the heat exchanger 201. As illustrated, the baffle 242 may extend within and across a portion of the chamber 224. For example, the baffle 242 may extend from the inner surface 312 of the fifth side 214 to the inner surface 316 of the sixth side 216 of the housing 204. The baffle 242 may be coupled to the inner surfaces 312, 316 via fasteners, pins, screws, or other mechanism, and may extend generally along the second side 208 of the housing 204 by a distance 273. The distance 273 may be substantially similar to the width 272 of the chamber 224 and thus, the baffle 242 may extend generally across the width 272 of the chamber 224 to direct air flow toward the heat exchanger 201 and mitigate bypass of the heat exchange 201 by the air flow.

FIGS. 9A and 9B are rear perspective views of an embodiment of the HVAC unit 100 that may employ the heating system 200. In particular, FIGS. 9A and 9B illustrate different return air section configurations of the HVAC unit 100. The illustrated embodiments of the HVAC unit 100 are also arranged in a side-flow configuration. That is, the HVAC units 100 are configured to discharge the supply air flow 113 via the supply air outlet 250 formed in the lateral side of the housing 102. As discussed above, the HVAC unit 100 includes multiple components enclosed within an internal volume of the housing 102, and the HVAC unit 100 may be configured to circulate one or more air flows through the HVAC unit 100 to condition the one or more air flows. In the illustrated embodiments, the housing 102 includes a first side 401 (e.g., first end, front end wall, front side), a second side 402 (e.g., second end, back end wall, back side) opposite the first side 401, a third side 403 (e.g., a first lateral side), a fourth side 404 (e.g., second lateral side) opposite the third side 403, a fifth side 405 (e.g., top side), and a sixth side 406 (e.g., base, bottom side) opposite the fifth side 405. Each HVAC unit 100 in FIGS. 9A and 9B also includes the return air section 110 configured to receive a return air flow, such as a return air flow from the building 10 of FIG. 1 , and the supply air section 112 configured to output or discharge the supply air flow 113 through a lateral side (e.g., third side 403) of the housing 102.

As illustrated in FIG. 9A, in some embodiments, the HVAC unit 100 may be oriented in an end-return configuration. For example, the return air section 110 may include an opening 420 formed within the second side 402 (e.g., back end 402) of the housing 102. The opening 420 (e.g., return air opening) may be configured to receive a return air flow 421 and direct the return air flow 421 through the HVAC unit 100 to be conditioned by one or more heat exchange components within the housing 102 (e.g., evaporator coil 114 of FIG. 5 , heater assembly 116), as discussed above. For example, the blower assembly 109 may operate to draw the return air flow 421 into the housing 102 via the opening 420.

As illustrated in FIG. 9B, in some embodiments, the HVAC unit 100 may be oriented in a side-return configuration. For example, the return air section 110 may include an opening 422 (e.g., return air opening) formed within the third side 403 (i.e., first lateral side 403) of the housing 102. Thus, the supply air outlet 250 and the opening 422 are formed in a common side (e.g., third side 403) of the housing 102. The opening 422 may be configured to receive the return air flow 421 and direct the return air flow 421 through the HVAC unit 100 to be conditioned by one or more heat exchange components within the housing 102 (e.g., evaporator coil 114 of FIG. 5 , heater assembly 116), as discussed above. For example, the blower assembly 104 may operate to draw the return air flow 421 into the housing 102 via the opening 422. Indeed, the embodiments disclosed herein may utilize different return air configurations (e.g., end-return, side-return), thereby enabling the embodiments disclosed herein to benefit multiple different applications and installations.

The heating system (e.g., heating assembly) discussed herein enables improved conditioning of one or more air flows directed through the heating system by positioning one or more heating coils downstream of multiple blowers relative to a direction of one or more air flows directed through the heating system. The heating coil may be disposed at a lateral end of a chamber proximate a supply air outlet, and the chamber may define an open or vacant section configured to receive a first air flow from a first blower and a heating section configured to receive a second air flow from a second blower. The heating coil of the heating system is positioned within the heating section, but the vacant section does not include a heating coil. Thus, the first and second air flows may be combined with one another in the chamber and may be directed across the heating coil as a combined air flow. As a result, a likelihood of overheating one or more of the air flows directed through the heating system is reduced, thereby increasing an efficiency of the HVAC system. Further, by positioning the heating coil in the heating section without positioning a heating coil in the vacant section, a pressure drop within the chamber is reduced (e.g., air flow through the vacant section is not impeded by a heating coil within the vacant section), thereby further increasing the efficiency of the HVAC system. Still further, by providing the vacant section of the heating system, different blower sizes may be utilized, thereby increasing the flexibility of the HVAC system to accommodate different blower sizes and configurations.

The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).

While certain features and embodiments of the disclosure have been illustrated and described, many modifications and changes may occur to those skilled in the art, such as variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, including temperatures and pressures, mounting arrangements, use of materials, colors, orientations, and so forth without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described, such as those unrelated to the presently contemplated best mode of carrying out the disclosure, or those unrelated to enabling the claimed disclosure. It should be noted that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation. 

1. A heating, ventilation, and air conditioning (HVAC) system, comprising: a housing defining a chamber configured to receive a first air flow and a second air flow, wherein the chamber comprises a vacant section and a heating section, and the heating section comprises a heating coil; a first blower configured to direct the first air flow into the vacant section of the chamber; and a second blower configured to direct the second air flow into the heating section of the chamber; wherein the housing is configured to direct the first air flow from the vacant section to the heating section to combine with the second air flow and configured to direct the first air flow and the second air flow across the heating coil.
 2. The HVAC system of claim 1, wherein the housing comprises a discharge outlet, and the housing is configured to direct the first air flow and the second air flow from the heating section through the discharge outlet.
 3. The HVAC system of claim 2, wherein the discharge outlet is formed in a lateral side of the housing.
 4. The HVAC system of claim 2, wherein a first portion of the heating coil is aligned with the second blower relative to a first flow direction of the second air flow into the heating section, and a second portion of the heating coil is offset from the second blower along a second flow direction of the second air flow through the discharge outlet.
 5. The HVAC system of claim 1, wherein the vacant section does not include a heat exchanger.
 6. The HVAC system of claim 1, wherein the heating coil is disposed at an oblique angle relative to a direction of the first air flow and the second air flow through the heating section.
 7. The HVAC system of claim 1, comprising a baffle disposed within the housing and upstream of the heating coil relative to a direction of the first air flow through the chamber.
 8. The heating assembly of claim 7, wherein the baffle is configured to deflect the first air flow toward the heating coil.
 9. A heating, ventilation, and air conditioning (HVAC) system, comprising: a housing defining a chamber; a first air flow path extending from a first blower, through an open section of the chamber, and through a heating section of the chamber to a discharge outlet of the housing; a second air flow path extending from a second blower through the heating section of the chamber to the discharge outlet of the housing; and a heating coil disposed within the heating section.
 10. The HVAC system of claim 9, comprising the first blower and the second blower, wherein the first blower is configured to direct a first air flow along a first air flow path through the chamber to the discharge outlet of the housing, and the second blower is configured to direct a second air flow along the second air flow path to the discharge outlet of the housing.
 11. The HVAC system of claim 10, wherein the housing comprises a first inlet configured to receive the first air flow from the first blower into the open section and a second inlet configured to receive the second air flow from the second blower into the heating section of the chamber.
 12. The HVAC system of claim 10, wherein the discharge outlet is formed within a lateral side of the housing.
 13. The HVAC system of claim 9, comprising a baffle disposed within the chamber and configured to deflect air flow traveling along the first air flow path, the second air flow path, or both, toward the heating coil.
 14. The HVAC system of claim 9, wherein the heating coil is disposed at an oblique angle relative to a direction of air flow through the chamber toward the discharge outlet.
 15. A heating system of a heating, ventilation, and air conditioning (HVAC) system, comprising: a housing defining a chamber comprising a vacant section and a heating section, wherein the housing comprises a first inlet configured to direct a first air flow into the vacant section and a second inlet configured to direct a second air flow into the heating section; and a heating coil disposed within the heating section, wherein the housing is configured to direct the first air flow from the vacant section to the heating section to combine the first air flow with the second air flow and configured to direct the first air flow and the second air flow across the heating coil.
 16. The heating system of claim 15, comprising: a first blower configured to direct the first air flow along a first air flow path extending from the first blower, through the first inlet, through the vacant section, through the heating section, and across the heating coil; and a second blower configured to direct the second air flow along a second air flow path extending from the second blower, through the second inlet, through the heating section, and across the heating coil.
 17. The heating system of claim 15, wherein a first portion of the heating coil is at least partially aligned with the second inlet relative to a direction of the second air flow through the second inlet.
 18. The heating system of claim 17, wherein a second portion of the heating coil is at least partially offset from the second inlet relative to the direction of the second air flow through the second inlet.
 19. The heating system of claim 18, comprising a supply air outlet formed within a lateral side of the housing and configured to discharge the first air flow and the second air flow from the housing.
 20. The heating system of claim 19, wherein the second portion of the heating coil is more proximate the supply air outlet than the first portion of the heating coil. 